Season 3, Episode 2
Production episode: 3×04
Original air date: September 27, 1968
Star date: 5431.4

Mission Summary:

On the bridge of Enterprise, Captain Kirk snaps at Chekov and Spock for no apparent reason. But it’s not just a case of the Mondays–Doctor McCoy explains that Kirk’s been short-tempered and (in scientific terms) acting like a total jackass to just about everyone onboard for days now. There’s no getting around it: Captain Kirk has come down with a severe case of douchebaggery.

Kirk turns to Sulu and orders him to change course.

KIRK: Come about to one eight five, mark three.
SULU: But Sir, that’ll lead us directly into the Romulan Neutral Zone.

Sulu, Chekov, Spock, and Uhura all look around at each other nervously. Mr. Scott and Uhura discuss very loudly that no order has come through from command to take this measure, and Kirk sharply instructs them to shut their pieholes.